DNS of Lean Premixed Flames

The paper presents results from the Direct Numerical Simulation of lean premixed hydrogen and methane flames. A new turbulence-generating technique, based on step-wise body forcing in physical space is introduced. It is stable, easy to implement and straight forward to use in the case of parallelization strategy based on domain decomposition. Flame-vortex interactions are also studied, both in two and three dimensions. A non-stationary method for straining the flame front, based on artificially generated Couette-like flow fields, is applied. It results pure strain without curvature. For the cases studied, much larger strain rate is achieved than that for the extinction limit in the case of twin opposed stationary flames. Despite the quite high strain rates achieved, no local extinction of the flame front has been achieved for the present simulations. All computations are carried out on the new CRAY-XE6 supercomputer at the High Performance Computing Center Stuttgart (HLRS). Numerical issues and results from a three-dimensional scaling test are presented and discussed.